Classifications

• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
  • F01K—STEAM ENGINE PLANTS; STEAM ACCUMULATORS; ENGINE PLANTS NOT OTHERWISE PROVIDED FOR; ENGINES USING SPECIAL WORKING FLUIDS OR CYCLES
  • F01K3/00—Plants characterised by the use of steam or heat accumulators, or intermediate steam heaters, therein
  • F01K3/12—Plants characterised by the use of steam or heat accumulators, or intermediate steam heaters, therein having two or more accumulators
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
  • F01K—STEAM ENGINE PLANTS; STEAM ACCUMULATORS; ENGINE PLANTS NOT OTHERWISE PROVIDED FOR; ENGINES USING SPECIAL WORKING FLUIDS OR CYCLES
  • F01K25/00—Plants or engines characterised by use of special working fluids, not otherwise provided for; Plants operating in closed cycles and not otherwise provided for
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
  • F02C—GAS-TURBINE PLANTS; AIR INTAKES FOR JET-PROPULSION PLANTS; CONTROLLING FUEL SUPPLY IN AIR-BREATHING JET-PROPULSION PLANTS
  • F02C1/00—Gas-turbine plants characterised by the use of hot gases or unheated pressurised gases, as the working fluid
  • F02C1/04—Gas-turbine plants characterised by the use of hot gases or unheated pressurised gases, as the working fluid the working fluid being heated indirectly
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
  • F02C—GAS-TURBINE PLANTS; AIR INTAKES FOR JET-PROPULSION PLANTS; CONTROLLING FUEL SUPPLY IN AIR-BREATHING JET-PROPULSION PLANTS
  • F02C6/00—Plural gas-turbine plants; Combinations of gas-turbine plants with other apparatus; Adaptations of gas-turbine plants for special use
  • F02C6/14—Gas-turbine plants having means for storing energy, e.g. for meeting peak loads

Definitions

• the present invention relates to an installation for storing and restoring electrical energy capable of storing several tens, or even several thousand MWh, as well as methods for storing electrical energy in the form of thermal energy in which an installation according to the invention is used. invention and a method of restoring an electrical energy from a thermal energy stored by a method according to the invention.
• the present invention relates to the storage of energy at high temperature and more particularly the storage of electrical energy, for the purpose of restoring it on the electrical network during peak consumption.
• the production of electric power is generally carried out by plants that use various fuels to produce energy, such as gas, oil, coal or lignite. Another way is to use nuclear fuel to produce heat which will then be converted into electrical energy in high pressure steam turbines.
• Renewable energies are also known, which, to a large extent, contribute to the production of electricity in different countries. Examples include hydraulic energy from dams, wind turbines, tidal turbines that draw their energy from marine currents, as well as various devices that recover the energy of the sea swell, or even solar energy.
• renewable energies are characterized by intermittent operation, and their integration into a network generally allows only to offload part of the conventional power plants, some of which are then either slowed down or simply stopped, waiting for a demand for power from the network.
• Steam turbines are also known which are used in nuclear power plants to convert the energy of water brought to very high temperature in the form of steam, into mechanical energy, then into electrical energy in end-coupled generators.
• shaft of steam turbines These steam turbines operate in a closed circuit with heat transfer fluid, water vapor phase upstream of the turbine and liquid water downstream of said turbine.
• dams are an excellent way of storing energy
• the sites are unfortunately limited in number and the storage of very large amounts of energy requires the mobilization of huge quantities of water. which must then be deducted from the available quotas, and then released at times when these quantities of water are not needed, for example for irrigation, the water being then more or less wasted.
• Several sites consist of a high reservoir and a low reservoir, usually high-capacity lakes, and during storage, the contents of the lower lake are pumped to the upper lake, for turbining in the opposite direction as soon as possible. when consumption peaks require additional power on the power grid.
• Another way is to store the energy in the form of compressed air, then retransform it into mechanical energy by means of piston engines, vane or turbine.
• Patent WO-2005-108758 discloses a method of storing energy in the form of heat in a subterranean chamber, the heat being generated by the compression of air initially at atmospheric pressure and at ambient temperature, the temperature within the buried storage being about 700 ° C.
• the gas, air circulates in open circuit, from the free atmosphere to the cavern during the storage phase, and from the cavern to the free atmosphere during the restitution phase. 'energy.
• regenerators commonly used in the fire industries, that is to say in blast furnaces, in the ceramic and terracotta industry, in the glass industry and cement plants, which consist of sending the hot burnt gases in large towers to heat the refractory masses they comprise so as to recover the calories of the gases, before releasing said gases into the atmosphere.
• the circulation of hot gas is stopped and fresh air is sent against the current, which then heats up in contact with the refractory materials to finally be directed towards the inlet of the refractory materials. ovens, or at the level of burners.
• These provisions make it possible to drastically reduce heat loss in energy intensive industrial processes.
• the problem is to store the electrical energy of conventional power plants, such as coal, gas, oil, or nuclear power plants, in order to be able to return it very quickly and in considerable quantities, in the electrical network during peak periods when the energy demand exceeds the production capacity.
• the present invention essentially consists in storing considerable amounts of electrical energy in the form of heat within masses of refractory products, the fluid allowing the transfer of energy being a gas, preferably a neutral gas, such as argon, then to restore this stored thermal energy potential, in the form of electrical energy.
• a gas preferably a neutral gas, such as argon
• the present invention provides an installation for storing and restoring electrical energy, characterized in that it comprises:
• first gas heating means adapted to heat the gas flowing in said second chamber
• gas cooling means flowing between one end of the first chamber and said compression means and expansion means, adapted to cool gas leaving said first chamber at this end before being expanded in said expansion means or gas respectively entering said first chamber after being compressed by said compression means.
• the two said upper (or lower) pipes can be either two parallel pipes ensuring the junction between the said turbine / compressor and the same enclosure or one of the two comprises a bypass pipe of the other before the said turbine / compressor.
• a storage installation and restitution of electrical energy comprises:
• insulated ducts for circulating gas in closed circuit between the two enclosures comprising first and second upper pipes between the upper ends of the two enclosures and the first and second lower pipes between the lower ends of the two enclosures, and
• first gas heating means adapted to heat gas inside said second chamber
• first gas compression means comprising a first electric motor adapted to be powered by an electrical energy to be stored for actuating a first compressor adapted to compress a gas from said upper end of the second chamber by a said second upper pipe to send it to said upper end of the first enclosure by a said first upper pipe, and
• first gas expansion means comprising a first turbine, adapted to relax the gas from said lower end of the first chamber by a first lower pipe to send it to said lower end of the second chamber by a second lower channel, and
• second gas compression means comprising capable of compressing the gas from said lower end of the second chamber by another second lower channel to send it to said lower end of the first chamber by another first lower channel;
• second gas expansion means comprising a second turbine adapted to relax the gas from said upper end of the first chamber by another first upper pipe to send to said upper end of the second chamber by another second upper channel, said second expansion means being able to actuate an electric generator capable of restoring electrical energy, and
• gas cooling means preferably a heat exchanger capable of cooling the gas flowing in said first lower ducts between on the one hand the lower end of the first chamber and on the other hand the output and inlet of said second compressor and respectively first turbine.
• the installation for storing and restoring the electrical energy according to the invention comprises second gas heating means capable of heating the gas flowing in a said second upper channel between the upper end of said second enclosure and the second said first compressor
• said first turbine is able to be actuated by said first compressor to which it is mechanically coupled
• said second turbine is coupled to an auxiliary electric motor capable of actuating it; said second compressor is actuated by said second turbine to which it is mechanically coupled.
• the plant according to the invention is filled with a neutral gas, preferably argon.
• this argon gas is advantageous because it is a permanent and neutral gas, therefore non-corrosive to the pipes, monoatomic gas having the advantage of being heated easily, so a limited compression ratio, and a reduced cost given its abundance.
• the installation has the characteristics according to which: said first chamber and first porous refractory material are capable of withstanding a temperature T1 of at least 750 ° C., preferably of at least 750 to 2000 0 C, more preferably from 1000 to 1500 ° C and
• said second turbine is sized to relax a gas at said temperature T1 while said first turbine, of less capacity than the second turbine, is sized to relax a gas from the ambient temperature TO to a temperature T3 of -80 to -20 0 C, and
• said second chamber and second porous refractory material are capable of withstanding a temperature T2 of at least 400 ° C., preferably of at least 400 ° C. at 1000 ° C., more preferably of 500 ° to 700 ° C., and said first compressor is sized to compress a gas at said temperature T2 while said second compressor, of less capacity than the first compressor, is sized to compress a gas of temperature T3 from -80 to -20 ° C. to ambient temperature.
• said first compressor is capable of delivering a higher volume flow rate than said first turbine and said second turbine is capable of delivering a higher volume flow rate than said second turbine.
• compressor and said first compressor and second turbine are made of carbon.
• said refractory materials have an intrinsic volume heat capacity of at least 2000 kJ xm "3 x K " 1 , more preferably at least 2800 kJ xm "3 x K “ 1 .
• said first and second porous refractory materials have a porosity of 20 to 60%.
• said first and second porous refractory materials consist of porous bricks assembled against each other, preferably traversed by cylindrical perforations arranged in parallel in the same longitudinal direction as said enclosure in which they are assembled, said perforations being more preferably of diameter 5 to 20 mm.
• said first and second porous refractory materials are made of fired clay, or ceramic products with high levels of compounds selected from oxides, magnesia, alumina and lime.
• Refractory materials include chamotte, magnesia, dolomite, mulite but also carbon.
• said first porous refractory material is made of second fired clay or chamotte, and said second porous refractory material is made of first fired clay.
• said first and second enclosures each have a volume of at least 5000 m3, preferably from 10000 to 45000 m3.
• the present invention also provides a method of storing electrical energy in the form of thermal energy in which an installation according to the invention is used, characterized in that, after an initial preheating step gas of said second chamber which is heated to temperature T 2 , said installation being filled with a permanent gas, initially at room temperature T 0 the following steps are carried out in which:
• the gas leaving the upper end of the second chamber at a temperature T 2 is heated to a temperature Ti greater than a temperature T 2 by compression in a said first compressor before being sent to the upper end of said first chamber, in which there is established a pressure P1 greater than the pressure P2 of the second chamber, said first compressor being driven by a first electric motor powered by the electrical energy to be stored, and
• the gas passes right through said first chamber between said upper end and its said lower end and it emerges from said lower end of the first chamber at an ambient temperature TO or a temperature T'1 greater than TO but less than T2 and 3) the gas is then cooled, if necessary, to an ambient temperature T0 by means of said gas cooling means, preferably of the heat exchanger type, downstream of the outlet of the lower end of the first enclosure, and
• the gas is then expanded through a said first turbine, preferably driven by said first compressor, at said pressure P2 of the second chamber lower than the pressure P1, the gas is thus cooled to a temperature T3 less than TO before to enter said second enclosure by its lower end, and
• step 5 the gas arrives at a cold temperature T3 at the bottom of the second chamber, which has the effect of yielding frigories to said second porous refractory material and thus cooling the lower part of the second chamber, which passes from the temperature T2 at the temperature T3.
• T3 the cold temperature
• the front or rather the thermal transition layer between the upper and lower hot parts of the second chamber progresses upwards and the lower part at the temperature T3 occupies a further volume.
• the electrical energy E1 used to supply power to the first compressor is therefore stored in the form of thermal energy in calories in the first enclosure and frigories in the second enclosure, this energy is a factor of the T1-T3 gradient.
• the storage is interrupted so that the lower part of the first chamber at said temperature T'1 represents at least
• said refractory materials are used whose properties and masses are such that:
• the pressures P1 is 2 to 4 bar absolute (2.105 to 4.105 Pa) and P2 is 0.5 to 1.5 bar absolute (0.5 to 1.5 105 Pa), and
• - TO is 10 ° to 50 ° C and T3 is -80 ° C to -2O 0 C, TT is optionally 20 ° to 150 ° C.
• TT is optionally 20 ° to 150 ° C.
• the present invention also provides a method for restoring an electrical energy from a thermal energy stored by a method according to the invention as defined above, characterized in that, after an initial startup phase in which one actuates said second compressor and said second turbine with said auxiliary electric motor, during which initial phase is established a pressure gradient between the pressure P'1 of the first chamber and a pressure P'2 less than P'1 of the second enclosure, such that P'1 is greater than P'2, preferably P'1 being greater than P1 and P'2 being less than P2, the following steps are carried out in which:
• the gas is then cooled to room temperature TO or T'1 by means of said cooling means before being introduced into said first chamber by its lower end (1 2 ) to join the lower part of said first chamber which is at said temperature T'1, and
• the gas is circulated through said first chamber, which has the effect of increasing the volume of refractory material of the lower part at said temperature T'1 and to reduce the volume of refractory material of the upper part (1a ) at said hot temperature T1, and
• each step 2) when the gas reaches the temperature T2 at the upper end of the second chamber which is initially not more than 20% at the temperature T2 or T'2 less than T2, and that the gas descends from the upper end to the lower end of the second chamber, the passage of gas in said second porous refractory material causes the gas to yield its calories to said second refractory material in the part upper chamber of the second chamber which is then heated to the temperature T2 while its lower unheated remains at the temperature T3.
• the front or rather the thermal transition layer between the upper hot and lower cold part of the second chamber progresses downwards and the lower part at the temperature T3 occupies a volume of less less important.
• step 5 the gas arrives at an ambient temperature T0 or T'1 at the bottom of the first enclosure, which has the effect of yielding frigories to said first porous refractory material and thus cooling the lower part of the first enclosure which passes from the temperature T1 to the temperature T'1.
• the front or rather the thermal transition layer between the upper and lower cold part of the first chamber progresses upwards and the upper part at the temperature T1 occupies a volume less and less important.
• the electrical energy Ei stored as heat energy in calories in the first chamber and frigories in the second chamber is thus converted into electrical energy E R from the mechanical energy released by said second turbine implemented during the expansion and cooling of the gas of the first enclosure
• the energy restitution process is interrupted so that an upper part of the first chamber is maintained at a said temperature T1, said upper part representing less than 20%, of preferably 10 to 20%, by volume of said first chamber, and / or a lower portion of the second chamber at said cold temperature T3 represents less than 20%, preferably 10 to 20%, volume of the second chamber.
• the efficiency of restitution of electrical energy by said electricity generator E R / EI greater than 60%, preferably 75 to 85%.
• T4 is 150 to 400 ° C.
• the pressure P'1 is 3 to 5 bar absolute (2.105 to 4.105 Pa) and P'2 is 1 to 1, 5 bar absolute (1 to 1.5 105 Pa).
• FIG. 1 represents the functional diagram of an installation according to the invention in a method of storing energy according to the invention, that is to say during the recharging phase of the first enclosure or hot source,
• FIG. 2 represents the functional diagram of the installation according to the invention in a restitution in the form of electrical energy of the thermal energy stored within the first enclosure or hot source
• FIG. 3 represents in section and in side view an enclosure of an installation according to the invention with a cutout showing cylindrical perforations
• FIGS. 3A and 3B show, in section along a horizontal plane, two variants of arrangement of refractory material elements of square and hexagonal shape respectively,
• FIG. 4 represents a thermodynamic cycle of perfect gas type, as well as compression and expansion of a real gas.
• FIG. 5 represents the thermodynamic cycle of recharging the first enclosure from electrical energy coming from the network.
• FIG. 6 represents the thermodynamic cycle of restitution of the energy coming from the first enclosure with a view to its reinjection into the network.
• FIGS. 7, 7A and 7B show the progression of a thermal transition layer of height h within a said first enclosure (FIG. 7) between the upper (FIG. 7A) and lower (FIG. 7B) ends.
• the device for storing electrical energy and restoring electrical energy according to the invention comprises:
• a first heat-insulated enclosure 1 comprising a steel wall 10 to 100 mm thick and filled with a first porous refractory material capable of withstanding the high temperatures and pressures of a neutral gas contained therein, T1 of 1000 to 1600 ° C., more particularly 1300 ° C. and P1, from 2 to 5 bara (absolute bar or 2.10 5 to 5.10 5 Pa).
• a second insulated enclosure 2 of the same volume of 10,000 to 15,000m 3 for example, comprising a steel wall of 10 to 100 mm and filled with a second porous refractory material capable of withstanding the T2 temperature and the gas pressure P2 inert it contains, namely T2 from 500 to 700 0 C, more particularly about 600 0 C.
• Said first chamber 1 and second chamber 2 are substantially completely filled with a porous refractory material 11 with a high heat volume, which will be described later.
• the device comprises closed circuit circulation lines between said first chamber 1 and second chamber 2 which allow the gas contained in the installation to pass through each chamber between two opposite ends 1-1 2 and 2i-2 2 , preferably located respectively at the high and low ends of said speakers.
• the circulation lines between said first and second enclosures further comprise gas compression / expansion means between the two enclosures, explained below.
• said first and second speakers are arranged vertically.
• the first enclosure 1 comprises at its upper end 1 i an upper pipe 1d, opening into the upper part 1a of the first enclosure, and at its lower end 1 2 a first lower pipe 1c opening into the part lower 1b of the first enclosure 1.
• the second chamber 2 comprises at its upper end 2i a second upper pipe 2d, opening into the upper part 2a of the second chamber 2, and at its lower end 2 2 a second lower pipe 2c opening into the lower part 2b of the second conduct 2.
• Said second enclosure 2 is coupled with a first heater 5a, preferably a heater comprising an electrical heater 5ai and a closed heating circuit 5a 3 between two ends of the second enclosure, the gas flowing in the heating pipe 5a 3 is heated by said first heater 5a
• a first compression / expansion group 3 is interposed between said first chamber 1 and second chamber 2.
• This first compression / expansion unit 3 comprises an electric motor 3a powered by an electric energy Ei, which makes it possible to actuate a first dynamic compressor 3b of axial or centrifugal type, and a first gas turbine 3c, itself coupled to said first compressor 3b, their respective shafts being coupled to each other as will be explained below.
• Said first compressor 3b is connected at the output to the upper end ⁇ ⁇ of said first chamber 1 by said first upper pipe 1d, and said first compressor 3b is connected at its inlet to the upper end 2i of said second enclosure 2 by said second upper pipe 2d.
• Said second upper pipe 2d is the feed pipe of the first compressor 3b and said first upper pipe 1d constituting the gas discharge pipe of the first compressor 3b after compression in storage cycle, as will be explained below.
• a second heater 5b preferably having a second electrical resistance 5a 2 , cooperates with said second upper duct 2d, said second heater 5b being interposed between the upper end 2i of the second enclosure 2 and the inlet of the first compressor 3b.
• Said first turbine 3c is connected to the lower end 1 2 of said first chamber 1 by said first lower pipe 1c, and said first turbine 3c is connected to the lower end 2 2 of said second chamber 2 by said second lower pipe 2c .
• Said first lower duct 1c serves to supply said first turbine 3c with gas discharged from the lower part 1b of the first enclosure 1, and the gas evacuating from said first turbine 3c joins the lower part 2b of said second enclosure 2 via said second lower channel 2c, when the device operates in storage cycle as will be explained below.
• a heat exchanger 6 cooperates with said first lower pipe 1c, between the lower end 1 2 of said first chamber 1 and said first turbine 3c.
• a second group 4 is interposed between said first enclosure 1 and said second enclosure 2 in the following manner.
• Said second electricity generator group 4 comprises a second electric motor 4d, coupled to a second gas turbine 4c and a second compressor 4b.
• This second electric motor 4d is a small motor essentially used to launch the second turbine 4c during the start of the cycle of restitution / destocking of the energy, as will be explained below.
• the second electricity generating unit 4 comprises an electric alternator 4a, coupled to the output shaft of said second gas turbine 4c and said second compressor 4b, so as to restore an electric energy E R when said second turbine 4c and second 4b compressor are activated, as will be explained below, in a cycle of energy destocking.
• Said second turbine 4c is supplied with gas by a pipe 1d 'derived from said first upper pipe 1d (also called first upper bypass line 1d'), or a pipe parallel to said first upper pipe, ensuring the connection between the upper end ⁇ ⁇ of the first chamber 1 and the second turbine 4c.
• the expanded gas leaving said second turbine 4c when the device operates in the destocking cycle, is evacuated to the upper end 2 ⁇ of the second chamber 2 via a pipe 2d 'derived from the second upper pipe 2d (also called second upper bypass line 2d'), or by a pipe parallel to said second upper pipe, thus ensuring the connection between the upper end 2- ⁇ of the second chamber and the second turbine 4c.
• Said second compressor 4b is supplied with gas by a branch pipe 2c 'of said second lower pipe 2c (also called second lower bypass pipe 2c') or a pipe parallel thereto thus ensuring the connection between the lower end 22 of the second chamber and the second compressor 4b. And, the gas is discharged from said second compressor 4b towards the lower end 1 2 of said first chamber 1, via a pipe 1c 'derived from said first lower pipe 1c (also called first lower bypass pipe 1c '), or a pipe parallel to said first lower pipe 1c, providing the connection between the lower end 1 2 and said second compressor 4b.
• a branch pipe 2c 'of said second lower pipe 2c also called second lower bypass pipe 2c'
• a pipe parallel thereto thus ensuring the connection between the lower end 22 of the second chamber and the second compressor 4b.
• the gas is discharged from said second compressor 4b towards the lower end 1 2 of said first chamber 1, via a pipe 1c 'derived from said first lower pipe 1c (also called first lower bypass pipe 1c '), or
• the second lower bypass line 2c ' provides the connection between the second compressor 4b and the second lower pipe 2c before the latter arrives at said first turbine 3c.
• the first upper bypass line 1d ' provides the connection between the second turbine 4c and the first upper pipe 1d before the latter arrives at said first compressor 3b.
• the second upper bypass line 2d ' provides the junction between the second turbine 4c and the second upper pipe 2d between said second heater 5b and said first compressor 3b.
• the first lower bypass line 1c ' provides the connection between the second compressor 4b and the first lower pipe 1c between said heat exchanger 6 and said first turbine 3c.
• the enclosures 1 and 2 are filled with a porous refractory material 11, allowing the gas to flow through said enclosures from one side to the other between their upper ends 1- ⁇ -2i and lower i 2 -2 2 .
• the porous refractory materials used in the first and second chambers have a porosity (void percentage) of 20 to 60%, which constitutes a good compromise between a sufficient heat exchange between the gas and the refractory materials on the one hand, and on the other hand, a sufficiently low pressure drop, while maintaining a sufficiently high circulation rate through said porous material.
• the device according to the invention is entirely filled with neutral gas, preferably argon, namely the pipe circuits mentioned above, the turbines and compressors, the heaters, and said first and second speakers.
• FIG. 3 shows in section and in side view an enclosure comprising a sealed metal outer casing 13, an internal insulation system 12 arranged against the wall of the metal outer casing 13 and a stack of blocks or bricks of refractory materials 11 having vertical channels H 1 in the form of perforations, preferably having a circular cross section with a diameter of 5 to 20 mm, passing through them integrally and arranged substantially uniformly, plane by plane, over the entire horizontal section of said first pregnant, as detailed in Figures 3A and 3B.
• the channels 1 I 1 of different superimposed blocks 11 are aligned relative to each other so as to allow the flow of gas in the longitudinal direction ZZ of the chamber 1, 2 between the two opposite ends of the enclosure without obstacle between the channels of different blocks superimposed in the same longitudinal direction ZZ.
• a widely open support structure 14, situated in the lower part of said enclosure, makes it possible to distribute the incoming or outgoing gases through the adjoined insulated lower conduits 1c, 2c, in a substantially uniform manner over the entire section of said enclosure and thus to direct them optimally, so with a minimum of losses, to the channels 1 I 1 vertically through said blocks of refractory material 11 in case of supply from below.
• FIG. 3A is a partial horizontal section in plan view along the plane AA of FIG. 3.
• the blocks of refractory materials 11 are square and perforated with a plurality of parallel circular cylindrical holes in the vertical direction ZZ perpendicular to the plane of FIG.
• the refractory material blocks 11 are advantageously in direct contact with the wall of the enclosure, at the level of the insulation 12 of said enclosure, so as to limit the direct and uncontrolled passages of the hot or cold gases in this zone.
• the blocks in the successive planes of blocks of refractory materials are advantageously offset from each other by a half-module or a half-block in staggered rows, so as to ensure overall stability within said enclosure, as shown in Figure 3.
• the blocks are stacked vertically on each other over the entire height of the enclosure, to form independent candles from each other and distant from 5 to 10 mm in all directions, which allows expansion during storage-retrieval cycles, while avoiding the risk of wear at the level of the horizontal planes AA during said storage-restitution cycles, when they are mounted in staggered rows as detailed in Figure 3.
• FIG. 3b shows refractory blocks 11a of hexagonal section, close to the insulating wall of a cylindrical enclosure.
• the connection with the insulating wall is done either by direct contact with the edge of a block, or by a form of insulating block 12a adapted to the curvature, or by stuffing an insulating material 12a, for example of the same type that the insulator 12 of said enclosure, is still a form of refractory block 12b adapted to the curvature.
• first top duct 1d and first upper duct 1d ' Vi
• second upper pipe 2d and the second upper bypass pipe 2d ' V 2 ,
• first lower duct 1c and first lower bypass duct 1c ' V 3
• second lower duct 2c and second lower duct bypass 2c' V 4
• first compressor group 3 (first compressor 3b and first turbine 3c) can be operated by disconnecting said second electricity generating unit 4 during a storage cycle. energy or, conversely, one can disconnect said first compressor 3 and open said bypass lines to operate said second compressor 4 during a cycle of energy destocking.
• the device according to the invention can, in fact, operate according to two different modes, namely:
• FIG. 1 shows the device in the phase of storing energy or recharging energy in the first enclosure 1.
• the complete installation is at ambient temperature TO of 10 to 20 ° C.
• the gas contained in the enclosures and pipes being therefore at this ambient temperature TO and the two enclosures are at the same initial pressure linked to the pressure of loading, for example from 1 to 1, 2 bara (absolute bar).
• the mass of refractory materials is then heated inside the second chamber 2 to a temperature T2 of 600 ° C.
• the gas of the second chamber is circulated in a closed loop between its upper ends 2i and lower 2 2 that is heated outside the enclosure using the first heater 5a, which heats the gas inside the heating pipe 5a 3 ensuring the loop between the lower ends 2 2 and upper 2i of the second enclosure outside thereof.
• the gas is circulated in the heating pipe 5a 3 through a fan 5a 5 and the first heater 5a comprises a first resistor 5a-1.
• a valve 5a 4 isolates the first heater 5a when it is out of service at the end of the initial preheating, thus avoiding unwanted transfers and recirculation of gas in a normal cycle.
• the valve 5a 4 is closed and the gas is sent via the second upper conduit 2d into the first compressor 3b, so as to heat it to the temperature T1 of 1200 to 1400 ° C, for example 1300 ° C output of said first compressor.
• a pressure gradient is established between the two chambers, the first chamber being raised to the pressure P1 of 2 to 4 baras (absolute bar, 2.10 5 to 4.10 5 Pa) and the pressure P2 in the second chamber being reduced to about 1 bara (1.10 5 Pa).
• the upper part 1a of refractory material therefore tends to the temperature T1 of 1300 0 C while the lower part 1b is established at a temperature T'1 of 20 to 100 0 C.
• the gas At the outlet at the lower end 1 2 of the first chamber, the gas must be expanded by the first turbine 3c to be restored to the pressure P2 of the second chamber before being reintroduced into the second chamber, expanded and cooled to a minimum. temperature T3 at the bottom of the second enclosure.
• T3 at the bottom of the second enclosure.
• the upper part 1a of refractory materials of the first hot chamber at the temperature T1 of 1300 0 C occupies an increasing volume of l enclosure, that is to say that the hot gas introduced at the upper end 1 i of the first chamber 1 gives its calories to said refractory materials and heats an increasingly large volume of refractory material of the first chamber.
• a front 1e which corresponds in fact to a temperature transition zone is shown schematically by a line in FIGS. 1 and 2.
• the upper parts 1a are hot at temperature T1 and lower 1b are cold at temperature T'1 from 20 to 100 ° C. C, move gradually downwards as gas circulation cycles during storage.
• the lower part 2b of the second chamber at the temperature T3 of at least -80 to -20 ° C. occupies a larger and larger volume of the enclosure 2.
• the front 2e schematizes a separation line which is in makes a transition zone between the lower part 2b at the temperature T3 and an upper part 2a at the temperature T2, moves progressively upwards as the different cycles of circulation of the gas progress.
• the first compressor 3b is powered by an electric motor 3a which consumes electrical energy E-i.
• the first turbine 3c is coupled to the first compressor 3b to the shaft from which it is coupled, so that the first turbine 3c supplies energy to the first compressor 3b in addition to the energy supplied by the first motor 3a.
• the temperature of the upper part 2a of the second chamber tends to decrease at a temperature T'2 less than T2, that is to say in below 600 ° C for example, 300 to 450 ° C.
• the gas exiting at the end is advantageously heated.
• upper 2 ⁇ of the second chamber with a second heater 5b comprising a second resistor 5a 2 for heating the gas flowing in the upper pipe 2d to maintain it at a temperature T2 of 600 0 C before it n arrives in the first compressor 3b.
• the engine 3a is adjusted so as to maintain the outlet temperature of the first compressor 3b at constant temperature T1 of the order of 1300 ° C.
• the temperature of the gas entering the second heater 5b is measured and the quantity of electric energy E 2 injected per second is adjusted in real time in the second heater 5b to bring the gas at substantially constant temperature T2.
• the power injected into the installation during these storage cycles will therefore correspond to the electrical energy Ei supplying the first electric motor 3a, supplemented with electrical energy E 2 supplying the second heater 5b.
• the heat exchanger 6 is supplied with a cooling fluid such as water or cold air at 10-20 ° C. to cool the gas coming out of the the first chamber at the temperature T'1 from 20 to 100 ° C. and bring it to the temperature TO from 10 to 20 ° C.
• the cooling fluid of the exchanger 6 leaves the exchanger 6 at 6d at a temperature of 50 to 100 0 C depending on the flow of air or cooling water.
• the heat exchanger 6 thus releases a thermal energy E 3 in the form of water heated to 50-100 ° C.
• This thermal energy E 3 is an energy which can not be stored in the system, but which can be recovered either at in a heat pump or still used in industrial processes or for urban heating. E 3 therefore constitutes, during a complete storage cycle, a loss which affects the overall efficiency of the device.
• a lower part 1b is maintained in the first chamber, representing 10 to 20% of the total volume of the chamber which remains at the temperature T'1 of 20 to 100 ° C.
• an upper part 2a of the chamber is maintained.
• This volume of 10 to 20% corresponds in fact to the volume of the thermal transition layer of height described later with reference to FIGS.
• FIG. 2 shows the energy recovery cycle stored in the first enclosure 1, in the form of electric energy Er.
• the first motor 3a When charging of the first chamber 1 is completed, it stops the first motor 3a, it actuates the various valves V i to V 4, for supplying the second group 4 with said first conduit and second upper branch pipe 1d ', 2d', and first conduit and second lower bypass line 1c ', 2c', the first compressor 3b and first turbine 3c no longer being supplied with gas.
• a small electric motor 4d is actuated which actuates the second turbine 4c and the second compressor 4b coupled thereto, so that establish a pressure gradient between the two enclosures 1 and 2 respectively with a pressure P'1 greater than P1 in the first chamber 1 and a temperature P'2 less than P2 in the second chamber 2.
• the second compressor sucks gas from the second chamber and sends it into the first chamber, which increases the pressure in said first chamber, thereby supplying gas to the second turbine, to finally return to the second enclosure and continue its circulation cycle.
• the turbine reaches its own speed, we stop feeding the small electric motor 4d.
• the second turbine 4c draws gas from the upper part of the first chamber to the second chamber by performing cooling and expansion of the gas.
• the losses at the turbine and compressor are such that P'1 / P'2> to P1 / P2.
• P'1 is from 3 to 5 baras and P'2 from 1 to 1, 5 baras.
• the motor 4d When the pressure gradient P'1 / P'2 is established, the motor 4d is cut.
• the gas in the lower part 2b of the second chamber is at the temperature T3 of -80 to -20 ° C. which was its temperature at the end of the storage cycle. And the gas is conveyed towards the second compressor 4b to be recompressed at the pressure P'1. It is concomitantly heated to the temperature T4, which temperature T4, because of the losses of the second compressor is greater than the temperature TO.
• T4 is of the order of 100-150 ° C.
• the gas at the temperature T4 greater than TO at the outlet of the second compressor 4b must therefore be cooled to the temperature T'1 by means of the heat exchanger 6 before being sent to the lower end 1 2 of the first enclosure 1, whose lower part 1b is at temperature T'1 from 20 to 120 ° C.
• the cooling of the gas output of the second compressor 4b during the destocking cycle has the effect that thermal energy E4 is lost by heating the coolant. But, this cooling of the gas the temperature T4 to T'1 makes it possible, during the energy storage cycles, to facilitate the cooling of the gas leaving the lower end I 1 of the first chamber from the temperature T'1 to the temperature TO in downstream of the heat exchanger so that the gas reaches room temperature TO, entering the first turbine 3c during energy storage cycles. Overall, the loss of thermal energy E4 during retrieval cycles is offset by a loss of thermal energy E3 at the level of the exchanger 6 less important during storage cycles. The thermal energies E3 + E4 correspond globally to the losses of the installation related to the T4-T0 gradient and due to the losses in the compressors and turbines.
• E R The energy restored by the system E R corresponds to the energy released by the second turbine 4c which actuates an electric generator-alternator 4a which makes it possible to restore energy in the form of electricity.
• E R more precisely corresponds to the energy released by the second turbine 4c less the energy consumed by the second compressor 4b coupled thereto.
• E R E 1 + E 2 - (E 3 + E 4 ) -E 5 .
• E 5 representing losses through insulation of enclosures, pipes, turbines and compressors and various accessories.
• the destocking is stopped before the first chamber is completely cooled and the second chamber is completely reheated so as to maintain a thermal transition layer in the part upper 1a corresponding to 10 to 20% of the volume of the enclosure which remains at the temperature T1, and concomitantly, a thermal transition layer in the lower part 2b of the second enclosure which remains at the temperature T3, this layer also representing 10 at 20% of the volume of the second speaker.
• This thermal transition layer in the upper part 2b of the second temperature chamber T2 facilitates the restoration of the pressure gradient between the two speakers P'1 / P'2 at the beginning of the energy recovery cycle corresponding to the same temperatures T1 / T2 respectively in the first / second speakers.
• Maintaining a thermal transition layer at one end of the first and second enclosures at the end of the storage cycle and at the end of the rendering cycle is also advantageous in terms of overall energy efficiency of the installation. Indeed, if one wanted to fully heat the first chamber at the end of the storage cycle, the gas leaving the lower end 1 i of the first chamber during the heating of the volume corresponding to the thermal transition layer at the end lower of the first enclosure, would come out at a temperature above the temperature T'1, which would imply a higher cooling energy E3 and therefore higher energy losses.
• the maintenance of a lower part 1b at the temperature T'1 at the end of storage and an upper part 2a at the temperature T2 in the second chamber at the end of storage facilitates the start of the restitution cycle, which requires a implementing the motor 4d for a shorter time to establish a stable operation with the temperature gradients T1 and T2 in the first and second speakers respectively at the pressures P'1 and P'2 during restitution.
• the maintenance of a hot top layer 1a at temperature T1 in the first chamber at the end of restitution and the maintenance of a cold bottom layer 2b at the temperature T3 at the end of the restitution cycle facilitates the start of the cycle. subsequent storage, decreasing the electrical energy E2 necessary to maintain the gas entering the first compressor 3b at the temperature T2.
• the sizing of the first compressor 3b / first turbine 3c implemented during the storage cycles, and second compressor 4b / second turbine 4c during retrieval cycles, are radically different given the different temperatures to which they are subjected. Indeed, the volume of a gas increasing with its temperature, the compressor and turbine operating with gases entering at high temperature will have to be larger. This is why during the storage phase, the first compressor 3b is a large compressor since it operates at a temperature T1 of 1300 ° C, while the first turbine 3c which operates at a temperature T3 of about -50 0 C will be a small turbine. Conversely, during destocking cycles, the second compressor 4c which operates at a temperature T3 of -50 ° C.
• the second turbine 4c which operates at a temperature T1 of approximately 1300 ° C. will be a large turbine.
• T1 temperature of approximately 1300 ° C.
• the implementation of a first small turbine 3c during the storage phase facilitates its drive by the first large compressor 3b.
• the implementation of a small second compressor 4b reduces energy losses and the energy E R corresponds to the energy released by the second turbine 41c less the energy consumed by the second compressor 4b.
• the front 1e separating the cold lower part 1b to T'1 and the upper part 1a hot to T1 of the first enclosure progressively moves upwards
• the front 2nd separating the upper hot part 2a at temperature T2 from the cold lower part 2b to temperature T3 of the second chamber moves progressively downwards.
• the commissioning of the exchanger 6 on the gas return circuit between the second compressor 4b and the lower part of the first enclosure 1, on the one hand, and secondly, the operation of the second turbine 4c are adjusted so as to maintain said temperatures T1 and T2 at constant values respectively, for example 1300 ° C. and 500 ° C., throughout the energy restitution cycle.
• the temperatures T1 and T2 are constant and identical on the cycles of loading / storage and unloading / energy release.
• FIG. 4 shows a graph corresponding to a thermodynamic cycle in which the abscissae represent the volumes and the ordinates represent the absolute pressures (bara).
• FIG. 4 It has been seen in FIG. 4 that if the same temperatures T1 and T2 are aimed at during expansion or compression with real machines, the pressure ratios are different. This means that the pressure ratios of the turbine-compressor assemblies used during the storage and retrieval phases must be different. For example in FIG. 4, during storage the high pressure is P b i and the low pressure P 3 , while during the restitution phase the high pressure is P b and the low pressure P a - ⁇ .
• FIGS. 5 and 6 show the thermodynamic cycles corresponding respectively to the energy storage and restitution cycles whose installations and processes are described in connection with FIGS. 1 and 2.
• thermodynamic cycles correspond to a unit volume gas, for example 1 m 3 , performing a complete cycle during which it acquires energy in a chamber or a compressor, then restores it in a turbine, or the other enclosure.
• Said unit volume carries out this thermodynamic cycle in a very short time compared to the complete duration of a storage or restitution cycle, and thus performs hundreds or thousands, even tens of thousands of thermodynamic cycles, that is, that is to say, it goes back so many times in the compressor, the turbine, the pipes and each of the speakers.
• FIG. 5 illustrates the storage phase described in FIG. 1.
• the gas coming from the upper part of the second enclosure enters the first compressor 3b at the temperature T2 at the point A. It is compressed and comes out at the temperature T1 at point B. It penetrates the mass of refractory 11 of the first chamber 1, passes through the mass of refractory by yielding its calories, which causes a gradual descent of the temperature front down.
• thermodynamic cycle of energy recovery detailed in FIG. 6 is as follows.
• the high temperature gas T1 leaves the first enclosure 1 from above, which corresponds to point B of the diagram.
• the gas is then turbinated at 4c where it returns the energy to the electric generator (ER) and is found at point A of the diagram at the temperature T2.
• ER electric generator
• the gas then passes into the second compressor 4b and emerges at a temperature T4 greater than the desired temperature TO: it then passes into the heat exchanger 6 where it restores the energy quota E4 to the outside, to end up at the temperature TO, therefore at point C of said diagram. Finally, it penetrates low into the first chamber where it recovers energy and heats up to reach the point B of said diagram, which causes a gradual rise of the temperature front 1e upwards, thus a global cooling of said first pregnant.
• FIG. 7 is shown, on the left in section in side view, the first chamber and the rising edge 1e separating the lower zone at a temperature of about 20 ° C., and the upper part at the temperature of about 1300 0 C.
• This rising edge corresponds in fact to a transition zone of a height h as detailed in the right graph of the same figure 7.
• the transition zone moves towards bottom ( Figure 7B), and during the restitution phase it moves upwards ( Figure 7A).
• the entire first chamber is not completely charged or completely discharged, which corresponds, as detailed in FIG. 7B, to limiting the charge cycle.
• this transition zone also exists in the second chamber but it corresponds to different temperatures, for example -50 0 C in the lower part, and 500 0 C in the upper part.
• the percentage of the heat content used corresponds to then at a height ⁇ H 2> said percentage used being preferably substantially identical to that of said first chamber, that is to say 80-90%.
• a second reason lies in the equality of temperatures T1 and T2 during the 2 storage / recovery phases, obtained by using different turbine-compressor assemblies working with different pressure ratios (P1 / P2 and P'1 / P'2 ).
• a third reason for the overall good efficiency comes from the fact that during the storage phase the losses of the hot compressor 3b are extracted as heat in the gas. This energy is stored in the refractory of the first chamber 1 as well as the heat pumped from the second chamber. This loss of energy from the hot compressor is largely recovered as useful work during the restitution phase.
• the fourth reason is the use of regenerators to exchange heat with the gas. It is indeed possible to arrange sets of refractory parts capable of operating at a very high temperature and having a very large exchange surface between the gas and the solids. This makes it possible to approach as well as possible the equality of the temperatures T1 and T2 during the 2 phases.
• the storage capacity is related to the mass of refractory.
• the arrangement according to the invention has the advantage that almost all of the mass of refractory is used to play a dual role: storage of heat and heat exchange with the gas.
• the last reason for the good overall efficiency results from the fact that the cold produced in the expansion of the turbine 3c during the storage phase is also stored in the chamber 2. During the restitution phase this allows the gas to be cooled before the compression by the compressor 4b, which reduces the energy absorbed by the compressor 4b, energy that decreases the energy restored E R.
• T1 the temperature of the gas at the inlet and T2 that at the outlet.
• T2 ⁇ T1 and W is then negative (power extracted from the gas).
• W is positive (power supplied to the gas).
• the density of the gas is proportional to the molar mass of the gas. However, it is easier to compress or relax a heavy gas than a light gas. The necessary machines are smaller and more economical with heavy gas than with light gas.
• the molar mass is respectively 40 for argon, 44 for CO2, 84 for krypton, 131 for xenon and 222 for radon.
• a mono-atomic gas such as helium, neon, argon or other rare gases of higher molar mass.
• the diatomic gases such as nitrogen and tri-atomic such as air or CO2 are very abundant and cheap, but at high temperature, are aggressive towards the metals constituting the envelope of the speakers, the pipes or the blades of the turbines and compressors, it is therefore advantageously used as gas in the device a neutral gas totally inert vis-à-vis the metal elements of the device, such as helium, neon, argon or other rare gases of higher molar mass.
• helium, neon and argon are present in ambient air in significant percentages and are available in large quantities at acceptable costs.
• argon is the most efficient gas for use in the device according to the invention, because it is monoatomic, it is inert at high and very high temperature vis-à-vis the metal components of the device according to the invention and it has a high molar mass and a low acquisition cost.
• Said first refractory material of the first chamber is, for example, chamotte, also called clay of second cooking ("fire clay") capable of withstanding 1200 0 Cm or a product with a high content of alumina and / or magnesia.
• the second refractory material in the second enclosure may be first fired clay.
• the refractory materials 11 are in the form of perforated bricks by parallel channels 5 to 20 mm in diameter and through-through, and arranged to allow the circulation and passage of gas through the channels in the longitudinal direction of the enclosure.
• the chamotte remains the most economical of all these products, but its maximum temperature remains very much lower than that of the others.
• E V. Cp. (T - TO) in which E is expressed in joules, V is the heated refractory volume, Cp the heat capacity in J / m3 / K, T the heating temperature and TO the initial temperature before heating.
• a device of 3000 MWh of capacity capable of storing and restoring a power of 100 MW, corresponding to a load in 40 hours and a restitution in 30 hours consists of:
• a first cylindrical enclosure 41m in diameter and 20m in height in which 16500 m3 of magnesia is installed, with a porosity of 25%, ie 3700Ot of refractory materials, and a second chamber 48m in diameter and 20m high in which is installed 22500 m3 of chamotte, having a porosity of 35%, or 29500 t of refractory materials, a storage group composed of a 100MW electric motor 3a, a compressor 117MW 3b, a turbine 3c 17MW, a restitution group composed of a generator 4a 100MW 1 of a turbine 4c 156MW, a compressor 4b 56MW.
• the internal volume of the complete installation, including the connecting pipes, but excluding the volume corresponding to the effective mass of refractory is approximately 35000 m 3 .
• Part of the gas is confined within the insulating materials that isolate the walls of the speakers hot refractory (about 12000 m3) and only a free volume of 23000 m3 can participate in the flow of gas.
• the plant is charged with argon before starting at the pressure of 1 bar, ie 2 baras, which corresponds to a volume of 70000Nm 3 of which 46000 Nm 3 can circulate.
• the pressure is 3 baras in the first chamber P1 and 0.9 baras in the second P2, while during unloading, these pressures are respectively 3.3 (P'1) and 0.6 (P1).
• the temperature T1 is 1256 ° C. while the temperature T2 is 600 ° C.
• the gas flow rate in the turbine 3c or the compressor 3b is 193 Nm 3 / s, that is to say at a thermodynamic cycle time according to FIG. 5 of 238 seconds, which corresponds to 600 gas circulation cycles for the duration of a full charge. Similar values are obtained for the unloading cycle.
• Centrifugal or axial turbines and compressors are generally limited in temperature due to the aggressiveness of the gases resulting from the combustion, but in the device according to the invention, said turbines and said compressors are operated in a closed circuit with a neutral gas such as argon, which allows for these machines operating points at a much higher temperature than in the art prior.
• a neutral gas such as argon
• the energy stored in the first and second speakers is not lost except in case of prolonged inactivity of the device in loading and unloading, the losses then taking place to the outside environment, mainly through the insulation 12 of said speakers.
• the thermal insulation is made with materials having a high porosity, such as ceramic fiber felt or ceramic foams. Calculations show that for the example cited above insulation 2m thick with conventional fibrous materials can limit the loss of energy to less than 1% per day.
• the large compressor 3b and the large turbine 4c that work at high temperature can advantageously be made with carbon-based materials.
• This body is mechanically resistant to very high temperatures, up to more than 2000 ° C. It is not usually used to build turbomachines because it oxidizes rapidly in oxidizing gases, such as air or the resulting products. of combustion. This limitation does not intervene here which allows to consider its use.
• Carbon turbines have already been made experimentally, or for rocket engines whose life is only a few minutes. In this application according to the invention, such turbines or compressors would have no limitation of life. In current machines made with metallic materials, it is necessary to cool the blades by an internal circulation of cold gas which is at the expense of efficiency. Despite this, mobile blades have a limited life due to the phenomenon of creep.
• two separate heaters 5a-5b have been described, but one and the same heater can be used as long as the routing of the pipes is adapted.

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